- Instructions pre & post laser performed in clinic
- Post Surgical Instructions
- Advice for all post-operative patients
The laser is connected to a slit lamp biomicroscope, exactly the same machine we use to assess you in the clinic environment. The laser beam is focused and targeted through a small lens on the surface of the eye.
Important concepts to take on board:
- The pupil will not be dilated for SLT or PI. However, we do advise not to drive back after the laser procedure to be absolutely safe.
- There is no recovery period or rest required after the procedure. Hence one can go back to work the day immediately after laser.
- On arrival for the day, we will administer lots of drops to:
- Anaesthetise the the eye, i.e. to make it numb and make the procedure as painless as possible. Despite our best endeavours, some patients may experience mild discomfort. Patients are emphasised that the drops numb the eye only, not the eyelids. Hence the touching the lids can evoke a reflex to squeeze or blink, which should be resisted as best as possible.
- Constrict the pupil to facilitate both types of laser:
- PI: the constricting drop (pilocarpine) acts to stretch and thin the iris. This reduces the amount of laser energy required to penetrate through the iris
- SLT: pilocarpine widens the irido-corneal angle. This exposes the trabecular meshwork, which is the area this laser aims to target.
- The actual laser takes ten minutes or so to perform. We request you wait one hour after the laser, so we can assess your eye pressure post procedure. The rationale behind this is:
- Both types of laser liberate inflammatory cells and pigment inside the eye, from either the iris or the trabecular meshwork. These cells float around inside the eye and settle in the trabecular region: they are a physical barrier so that fluid cannot leave the eye and as such the pressure shoots up.
- We attempt to circumvent this pressure increase by administering another drop called iopidine
- Hence your eye will be marinated with lots of drops!
- Don’t be perturbed by transient symptoms following laser:
- Visual blurring
- Light directed to the eye can ‘blanch’ the retina, giving a dazzled appearance. This can last minutes to an hour or so
- The constricting drops (pilocarpine) can cause a brow ache
- Anything untoward, please let the team know
- Visual blurring
- And then, we will send you home with even more drops!
- Steroids to ensure the inflammatory and pigment cells do not settle and obstruct the outflow drainage pathway of the eye.
- Continue the pressure reducing drops that you were taking prior to the laser procedure until your clinic evaluation. This may be modulated and even stopped by your consultant in the clinic
- Follow up in the clinic is ideally done at one week for PI and 8 weeks for SLT. The objective of this appointment is twofold:
- Following PI, it is vital to reassess the irido-corneal angle to see if the laser has widened it.
- If it hasn’t, the options of careful/regular gonioscopic assessments versus lens extraction need to be discussed
- Pressure evaluation
- The SLT will have had ample time to exert its maximal affect by six weeks. The point of assessing the pressure is to ensure medical therapy is not required to work synergistically with SLT
Instructions pre & post MIGS surgery
- This can lead to an exaggerated inflammatory response called fibrinous uveitis. We attempt to prevent this by giving a steroid injection intra-operatively.
- Intense steroid regime is prescribed in the post-operative period to prevent this fibrinous uveitis occurring
- A post-operative follow up appointment at 6 weeks is usually made. This is when the laser starts to have its maximal effect. Hence patients are requested to:
- Continue their pressure reducing drops that they were on prior to surgery for 5 weeks after the day of the operation
- Stop these drops at 5 weeks
- Be reviewed off drops at week 6 to assess the pressure
- Any reduction in pressure, red eye or loss of vision prior to your appointment, please report to eye casualty for an assessment
- The implant is anchored in a position whereby half is inside the eye (in the anterior chamber) and half is under the skin of the eye (the conjunctiva). Whilst it is firmly anchored, it is wise not to aggravate it unduly by aggressively rubbing one’s eyes
- Scarring in this sub-conjunctival space is detrimental to all glaucoma surgery and is the case for the Xen implant. To protect the conjunctiva as much as possible preservative free minims (both steroids and antibiotics) is prescribed: it is important to use the preservative free variants
- Close monitoring in the clinic by a glaucoma specialist is key: any semblance of scarring, an anti-scarring injection should be given to break up the scarring bands. Regular monitoring is crucial.
- Hence an appointment one-two weeks post operatively is the norm. Note, the fluid inside the starts to drain through the stent immediately: hence stop the pressure reducing medication that you were prescribed prior to surgery immediately after surgery.
- Instructions following ANY glaucoma surgical procedure
As a surgeon, the greatest fear that keeps me up at night is infection. Whilst thankfully rare, infection can track back into the eye and affect each layer, called endophthalmitis. This is sight threatening and the prognosis of endophthalmitis is exquisitely poor.
The most common cause of infection following eye surgery is bacteria entering the eye at the time of surgery from the eye lashes of the patient. We all have bacteria naturally in and on our body, for instance our lashes contain various strands of staphylococcus and streptococcus. At the time of surgery, we make great attempts to prevent these bacteria entering the eye by:
- Cleaning and sterilising the eye
- Spreading the eyelashes away from the surgical operating field by a clear surgical drape. It is important, that if you are having surgery under local anaesthesia, not to squeeze whilst we drape you at the beginning of the operation. The motion could disrupt the act of everting the lashes away from the site of surgery and inadvertently introduce bacteria into this field.
- Giving antibiotics into the eye at the conclusion of the surgery
This being said, the most likely timeframe for infection to occur is within 4-5 days from the date of surgery. Hence you must attend eye casualty immediately if you get:
- Reduction in vision
- Increased pain
- Yellow discharge
- Red eye
All of these could potentially indicate an infection and you will be assessed by a casualty officer. The progression of the infection dictates our management plan, which could include:
- Antibiotics injected into the eye
- Small fluid samples taken to be sent to our microbiology laboratory
- Systemic antibiotics given either orally or through the veins
- Intensive antibiotic eye drops
At this stage, it is advisable to keep the patient admitted into hospital to monitor progress and ensure the medication is administered correctly.
- Do not do heavy lifting for a month or so
- The stitches we use in conventional glaucoma surgery (trab and tube surgery), are thinner than a strand of human hair
- By doing heavy lifting, the increased intra-abdominal pressure is transmitted to the eye and potentially can damage these stitches or cause wounds to open
- No swimming for a month or so
- Infections in the pool can cause a severe infection in the eye
- Flying is not prohibited
- The only ophthalmic surgery that precludes you from flying temporarily is vitrectomy with gas insertion (typically done for retinal detachment)
- To prevent inadvertent rubbing of your eye whilst sleeping, it is prudent to tape the plastic shield over the eye during bed time for the first month or so. During the day, it must be kept off and drop administered
- With the exception of ECP, the pressure reducing drops that were prescribed prior to surgery should be stopped immediately after surgery. Depending on the type of surgery done and your response to the surgery, the drops may be re-introduced later if indicated.